Setting up fan drive gears on 70 jd gas

   / Setting up fan drive gears on 70 jd gas #1  

mdross1

Silver Member
Joined
Oct 13, 2012
Messages
131
Location
Windham
Tractor
John Deere 70
Had to replace original fan drive gears on 70 gas as per manual using the high backlash reading using dail indicator.Needed to tear governor housing back apart drain hole was pugged noticed gears are bad again.Installed a second set this time with more clearance,needing to know pulled the vent pump and again chipped teeth on ring gear.Any opinions from the experienced?
 
   / Setting up fan drive gears on 70 jd gas #2  
Governor shaft bearings are known to go bad. Are yours okay?
 
   / Setting up fan drive gears on 70 jd gas
  • Thread Starter
#3  
The gear side bearing is new,the dist side felt very smooth.It is the outer edges of the ring gear teeth are being chipped even with the backlash set correctly almost has to be the pinion depth that is not right.
 
   / Setting up fan drive gears on 70 jd gas
  • Thread Starter
#4  
Last of the two times apart for second gear change,studied how to get the distributor side bearing off could not find or see how.Will fire the tractor again and run it then pull it back apart to check.
 
   / Setting up fan drive gears on 70 jd gas
  • Thread Starter
#5  
Talked to a pro yesterday finally have the lowdown on getting the governor up to speed,as soon as the new bearing shows up will tear into it one more time,finally with plenty of confidence.Got the new radiator core in yesterday.
 
   / Setting up fan drive gears on 70 jd gas #6  
Best to replace in pairs but that's not always an option. How much fan blade movement do you get when its all said and done? Should be about a 1/4" at the outside edge. Does it whine when the tractor is running? Carefully try moving the shaft around at the front mount. Also loosen the bolts either on the side cover or on the front of the governor when its running. If it gets quieter than you need another shim. A dial indicator should be the most precise but its got 60 years of wear so whatever it takes to make it quiet! One other thing, where the distributor side bearing rides in the gov housing gets loose. Might want to check that.

Tim
 
   / Setting up fan drive gears on 70 jd gas
  • Thread Starter
#7  
Nothing wrong with the bearings,both will be new when reassembled.Decided to strip both shafts and check for runout.Both had .010+ so luckily found nos shafts and gear set (very expensive) but when back together should be the last time.Been sleeping good since then.The governor housing has zero wear in the bearing area.
 
 
Top